This invention relates to patient transfer and lifting devices.
There is a need for a compact, lightweight and easily portable patient transfer device to assist caregivers in transferring patients between beds, wheelchairs, cars, etc.; for use in the home, in institutional settings, and in the outside world. Transferring of disabled patients is a leading cause of injury in the health-care industry, with the nursing occupation having among the highest incidence of back injury, despite the prior art and the availability of commercial patient lifts. These lifts are under-utilized for a number of reasons, such as restricted space in many hospital wards and bathrooms, cumbersome operating requirements, the indignity involved in the mode of transport, the additional time required for performing the transfer, and the unavailability of the lift at both the patient""s starting and destination locations. A device is required that can work in confined spaces, is simple to set up and use, feels safe, secure and is not intimidating for the patient, and can be transported with the patient.
The problem is pervasive in the home health care industry as well, where spaces are not designed for safe patient transfers, and the caregiver is often alone and has no help during lifts. Since lifts are available in less than 10 percent of the homes visited by home health care professionals, a device that can be easily brought from home to home is also required.
In addition, many patients are essentially home-bound due to the unavailability of a conveniently portable lift, reducing their quality of life unnecessarily. A device is required that would allow a single, and often elderly, spouse to bring their disabled spouse out of the house, on car trips, cruises, etc. The device must be versatile and be able to maneuver in the confined spaces found in many homes and public accommodations. It must also be easily transported, and must transfer patients in a dignified manner if it is to be used outside the home.
While this field contains considerable prior art, these devices have proven inadequate. U.S. Pat. No. 4,805,248 to Lunau (1989) is typical of ceiling-mounted patient lifts. While effective, these are limited to use in very well defined areas. U.S. Pat. No. 3,137,011 to Fischer (1964) is representative of a common type of mobile patient lift. A major disadvantage of this design is that the patients are essentially suspended from a hook. The resultant swaying motion during transfer is disconcerting to most patients. In addition, the patient is transported in a partially reclined position, increasing their sense of helplessness and indignity, particularly if used outside in public. U.S. Pat. No. 4,399,572 to Johansson (1983) overcomes the swaying problem by using short straps attached to a rigid seat, for side-loading into a car. The rigid seat presents a difficulty in terms of initially placing the seat under the patient. Additionally, this patent teaches the use of a wide base to surround the wheelchair, making it inoperable in confined spaces. Additionally, the side-loading design prevents the lift from being used on both sides of the vehicle. U.S. Pat. No. 3,914,808 to Woods (1975) teaches the use of a short flexible sling in a front-loading orientation, with a pivoting column. Here again, the base must be relatively wide in order to avoid tipping as the column is rotated, and there is no means for compactly transporting or storing the lift. Additionally, the use of a fixed length sling requires that the patient be sitting precisely on the center of the sling, to avoid tipping the patient as the column is raised. This increases the time and training required to use the lift. U.S. Pat. No. 3,940,808 to Petrini (1976) similarly describes a pivoting column, necessitating a relatively wide base, and a rigid seat, complicating the placement of the sling on the patient. U.S. Pat. No. 4,719,655 to Dean (1988) describes a lift used with a short sling in a front-facing orientation, the sling being adjustable using straps and buckles. However, this lift cannot be rolled once the patient is raised, since the jack is then resting on the floor. It also requires that a separate back support be installed. U.S. Pat. No. 2,962,730 to Carnes (1960) and U.S. Pat. No. 2,539,346 to Feist (1951) describe a lift used with a fixed-length sling having no integral back support, and having no means of compactly transporting or storing the lift. U.S. Pat. No. 4,737,997 to Lamson (1988) features a narrow base. The two-wheel design of this lift would be too unstable to safely support a patient, however. It also is limited to a narrow range of lifting heights. U.S. Pat. No. 4,704,749 to Aubert (1987) describes a lift intended to allow a partially disabled patient to transfer themselves, without the need for a health care provider. A limitation of this design is that the patient""s weight is supported under the arms, which tends to be unnatural and uncomfortable and requires a significant amount of shoulder strength. It is therefore appropriate for a relatively small percentage of patients, and is also relatively expensive. U.S. Pat. No. 4,435,863 to Lerich describes a transporting device consisting of a pivoting chest pad to which the patient is strapped. Pivoting the pad causes the patient to be pivoted out of a seat. He is then transferred in a bent-over orientation and pivoted down onto a receiving surface. This design results in an undignified transfer position, and is fairly limited in terms of the difference in height between initial and final surfaces. It also results in part of the weight being carried on the patient""s chest, making it inappropriate for patients with breathing difficulty, who use ventilators or who wear cervical spine stabilization devices. U.S. Pat. No. 4,510,633 to Thorne (1985), and U.S. Pat. No. 5,233,708 to Winston (1993) are similar in that the patient is strapped to a rolling frame with their knees supporting part of the load. The range of transfer surface heights is relatively limited since the patients feet cannot leave the floor level. U.S. Pat. No. 4,157,593 to Kristensson (1979) and U.S. Pat. No. 4,545,085 to Feldt (1985) overcome this latter limitation by raising a separate sub-frame, at the expense of additional weight and complexity. They all require that a patient be strapped into the device, a somewhat undignified posture when used in public. In addition, they all require that the patient""s knees be bent 90 degrees, making it unsuitable for amputees, individuals with arthritis or leg injuries, a large proportion of the individuals who would be in need of assistance.
In addition, none of the previously mentioned patents adequately address the issue of portability. U.S. Pat. No. 5,153,953 describes a lift which must be disassembled for transport. In addition, the individual pieces are relatively large and cumbersome. The base must be large enough to surround a wheelchair, and the column does not telescope, so it must be tall enough to accommodate the maximum lift height. U.S. Pat. No. 5,560,054 to Simon (1996) describes a folding lift design to minimize storage space. Even when folded, however, this lift is quite large due to its overhead boom design, and certainly not readily transportable. It also shares the problems associated with dangling from a hook described previously. In addition, the method of folding the legs vertically, in the direction of the applied load, represents a potentially dangerous failure mode should the highly loaded locking mechanism fail while transferring a patient. U.S. Pat. No. 5,319,817 to Hay (1994) describes a gurney with folding legs and transport surface, so as to occupy less aisle space when stored. The folding mechanism is relatively complex, however, and it is not useful for transferring patients to wheelchairs or cars. Arjo, Inc. (Morton Grove, Ill.) markets a patient lift whose legs fold upward for portability and compact storage. However, their lift is too heavy to be lifted by most individuals, and it cannot be transported on the back of a wheelchair. As noted above, the method of folding the legs vertically presents a potential safety problem should the legs not properly lock during use. U.S. Pat. No. 6,161,232 to Vos Schroeter (2000) describes an overhead lift from which a patient is suspended. While the width can be narrowed to pass through doorways, the length remains the same, and its height is inherently large due to its overhead design. In addition, the requirement for two parallel drives make it inherently expensive, heavy, and non-portable. U.S. Pat. No. 3,222,029 to Hildemann (1965) presents a lift who""s width can be narrowed for storage. However, the device suspends the patient from a hook, with the attendant swaying problems noted above. In addition, the lift can only roll freely when fully open, since the wheels will only pivot freely when the caster""s swing axis is perpendicular to the floor.
None of the previous patents address the problem of insuring that a lift is available at both the patient""s starting and final locations. U.S. Pat. No. 4,999,862 to Hefty (1991) attempts to address this by incorporating an overhead crane onto a wheelchair. This approach suffers from the limitations of being relatively complex and expensive, and requires modification of the wheelchair. U.S. Pat. No. 5,520,403 to Bergstrom (1996) and U.S. Pat. No. 5,060,960 to Branscumb (1991) also require customized wheelchairs. U.S. Pat. No. 4,288,124 to Hamilton (1981) presents a transfer stool that can be mounted to a standard wheelchair with minimum modification. It does not provide for patient support during transfer to the stool, however, and can not be used to transfer between different height surfaces.
Accordingly, several objects and advantages of the present invention are:
(a) to provide a lift that can be used in confined spaces;
(b) to provide a lift that is easily transportable between locations;
(c) to provide a lift that transports patients in a natural, comfortable and dignified posture;
(d) to provide a lift that is easy to use;
(e) to provide a lift that feels secure and is not intimidating to the patient;
(f) to provide a lift that provides for faster patient transfers;
(g) to provide a lift that requires minimal effort by a single care provider;
(h) to provide a lift that can be mounted on a standard wheelchair so as to be readily available at both starting and destination locations;
(i) to provide a lift that allows the patient the opportunity to participate is his transfer;
(j) to provide a lift that is versatile and adaptable to a variety of settings;
(k) to provide a lift that can be placed into a car trunk without disassembly;
(l) to provide a lift that provides support for the patient during transfer;
(m) to provide a lift that is economical to manufacture;
(n) to provide a lift that is compact and lightweight;
(o) to provide a lift that can be stored in confined spaces;
(p) to provide a lift that can be used to transfer patients between different height surfaces such as beds, wheelchairs, chairs and cars.
Further objects and advantages of this invention will become apparent from a consideration of the drawings and ensuing description.